1. Field of the Invention
The present invention relates to a vehicle deceleration warning apparatus which would provide early warning of an impending stop by advance brake light activation, prior to actuation of the brake pedal.
2. The Prior Art
Rear-end automobile collisions account for approximately two-thirds of the auto accidents occurring worldwide. The majority of all chain accidents occur during rush-hour traffic jams. Under those conditions, drivers often do not have enough time to react to one anothers movements. As it appears to be impossible to force drivers to maintain safe distances between cars, other solutions must be found.
One recently implemented solution is the center-high-mounted-stop lamp (CHMSL) introduced in the U.S. in the early 1980's. Pursuant to Federal regulation 49 CFR 571.108 (Standard 108) the installation of this device in all new cars became a mandatory requirement. The CHMSL provides significant advantages and benefits in preventing some rear-end collisions.
However, rear-end collisions are still occurring at an alarming rate. Other devices have been developed which are directed to the prevention of rear-end collisions and their severity by advancing the reaction-braking response in emergency braking situations; this in contrast to the CHMSL method which reduces driver's reaction time in emergency-braking situations.
The following patents disclose various types of early warning systems.
______________________________________ Patent No. Inventor ______________________________________ 3,171,914 Ohanian 3,171,917 Leichsenring 3,395,388 Hendrickson 3,497,871 Damico 3,596,020 Warren 3,601,796 Mortimer 3,881,078 Kazanecki 3,911,394 Shames 3,912,892 Morehouse 3,921,750 Shames 4,021,775 Leu 4,173,012 Burger 4,686,503 Miller ______________________________________
Mortimer discloses an accelerator release signal light delay actuator which delays actuation of the brake light upon release of the driver's foot from the accelerator pedal for 5 or 6 seconds following release of the accelerator. After the delay period is past, if the brake has not yet been applied, the brake lights are turned on at a intensity less than the intensity available when the brakes are actually actuated. Thus, the possibility of false indication is decreased since the person behind the front car recognizes the decreased intensity of the light indicating that the brake has not itself been actuated.
Morehouse discloses an automobile deceleration warning system in which an auxiliary pedal is positioned above the main accelerator pedal. A normally opened switch is positioned between the two pedals. Upon release of the auxiliary pedal, the switch closes, thereby lighting the brake light. According to the patent, a resistor may be included which reduces the current flow to the brake lights, thus lighting the brake lights at a lower intensity when the lights are actuated in response to the lifting of the accelerator pedal as compared with the intensity of the brake lights when the brakes are actually applied.
The Shames patents disclose a vehicle brake light warning system in which the brake lights are activated for a given period of time upon release of the accelerator pedal. This time period is sufficient for the driver to lift his foot from the accelerator to the brake pedal. If the brakes are not applied within that time period, the brake lights are turned off.
Burger, Leu, Kazanecki, Warren, Ohanian and Miller all disclose alternate systems for providing early warning of brake activation by turning on the brake light or alternative lights upon release of the accelerator pedal.
However, all of the above-noted patents suffer from a significant disadvantage in that no differentiation is made between panic stop behavior and non-panic stop behavior. Each of these devices result in a high rate of "false alarms" which can lead to a decrease in the overall warning value of the stop lamp signal itself, due to a "cry wolf" phenomenon. This leads to a significant reduction in the effectiveness of these systems.
European Pat. No. 0 219 858 discloses a device which remains ineffective in non-emergency cases. The advanced braking light device (ABLD) is an electronic device installed on a vehicle accelerator pedal. When a leading vehicle driver attempts a panic-braking operation, the accelerator pedal is released by a sudden movement when the driver's leg is shifted to apply the brake pedal as quickly as possible.
The sudden release is sensed by the ABLD and immediately after the accelerator pedal is released, the stop lights are activated. This advanced activation of the stop lights, by a fraction of 0.2-0.3 seconds, which is approximately the time necessary for the driver to move his leg from the accelerator to the brake, enables the following vehicle driver to start his reaction to the braking at an earlier stage, thus improving his chances of preventing a collision or reducing the severity thereof. The brake lights remain lit for only 1 second if the brake pedal is not actuated.
The ABLD device 10 is shown in FIGS. 1 and 2 of the present application. When the bellows 14 is in its collapsed position, i.e., the drivers foot is on the pedal, electrical contacts 38 and 41 are separated and the circuit is opened. Upon sudden release of the accelerator pedal, the switching device 40 closes and bellows 14 becomes momentarily effective to generate sub-pressure inside, thereby causing an air suction effect through the opening. This forces the flap 54 to lift and make electrical contact with the rim 22, and short-circuit the terminals 56 and 58 through the coil spring 26. By actuation of the relay 62, the brake lights 70 are turned on.
A moderate movement will not effect actuation of the brake lights since air will gradually refill the chamber within bellows 14 without causing an air-lift or suction phenomena of the required amount to overcome the coil spring force 26. The patent also discloses an electrical version of the device which does not include the bellows 14. A potentiometer is provided so as to avoid brake light activation based on slower movements of the driver's foot wherein movements below as certain speed will have no effect on the system.
The ABLD of the European patent application is bulky, complicated and expensive to manufacture. In addition, because of the number of moving parts and the provision of a flexible rubber bellows, this device is likely to wear out and break frequently thus reducing its cost effectiveness.
Patents have been issued which disclose the use of a vehicle pedal operated switch mounted on an upper end portion of the arm connected to the foot pedal (see U.S. Pat. Nos. 3,763,975, 3,846,599, and 4,333,070). It has been known to use piezoelectric crystals in key switches which form a keyboard (see U.S. Pat. No. 4,737,767).